1 2885 97 G9A PARTICIPATES IN NERVE INJURY-INDUCED KCNA2 DOWNREGULATION IN PRIMARY SENSORY NEURONS. NERVE INJURY-INDUCED DOWNREGULATION OF VOLTAGE-GATED POTASSIUM CHANNEL SUBUNIT KCNA2 IN THE DORSAL ROOT GANGLION (DRG) IS CRITICAL FOR DRG NEURONAL EXCITABILITY AND NEUROPATHIC PAIN GENESIS. HOWEVER, HOW NERVE INJURY CAUSES THIS DOWNREGULATION IS STILL ELUSIVE. EUCHROMATIC HISTONE-LYSINE N-METHYLTRANSFERASE 2, ALSO KNOWN AS G9A, METHYLATES HISTONE H3 ON LYSINE RESIDUE 9 TO PREDOMINANTLY PRODUCE A DYNAMIC HISTONE DIMETHYLATION, RESULTING IN CONDENSED CHROMATIN AND GENE TRANSCRIPTIONAL REPRESSION. WE SHOWED HERE THAT BLOCKING NERVE INJURY-INDUCED INCREASE IN G9A RESCUED KCNA2 MRNA AND PROTEIN EXPRESSION IN THE AXOTOMIZED DRG AND ATTENUATED THE DEVELOPMENT OF NERVE INJURY-INDUCED PAIN HYPERSENSITIVITY. MIMICKING THIS INCREASE DECREASED KCNA2 MRNA AND PROTEIN EXPRESSION, REDUCED KV CURRENT, AND INCREASED EXCITABILITY IN THE DRG NEURONS AND LED TO SPINAL CORD CENTRAL SENSITIZATION AND NEUROPATHIC PAIN-LIKE SYMPTOMS. G9A MRNA IS CO-LOCALIZED WITH KCNA2 MRNA IN THE DRG NEURONS. THESE FINDINGS INDICATE THAT G9A CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT THROUGH EPIGENETIC SILENCING OF KCNA2 IN THE AXOTOMIZED DRG. 2016 2 1166 43 CONTRIBUTION OF DNMT1 TO NEUROPATHIC PAIN GENESIS PARTIALLY THROUGH EPIGENETICALLY REPRESSING KCNA2 IN PRIMARY AFFERENT NEURONS. EXPRESSIONAL CHANGES OF PAIN-ASSOCIATED GENES IN PRIMARY SENSORY NEURONS OF DRG ARE CRITICAL FOR NEUROPATHIC PAIN GENESIS. DNA METHYLTRANSFERASE (DNMT)-TRIGGERED DNA METHYLATION SILENCES GENE EXPRESSION. WE SHOW HERE THAT DNMT1, A CANONICAL MAINTENANCE METHYLTRANSFERASE, ACTS AS THE DE NOVO DNMT AND IS REQUIRED FOR NEUROPATHIC PAIN GENESIS LIKELY THROUGH REPRESSING AT LEAST DRG KCNA2 GENE EXPRESSION IN MALE MICE. PERIPHERAL NERVE INJURY UPREGULATED DNMT1 EXPRESSION IN THE INJURED DRG THROUGH THE TRANSCRIPTION FACTOR CAMP RESPONSE ELEMENT BINDING PROTEIN-TRIGGERED TRANSCRIPTIONAL ACTIVATION OF DNMT1 GENE. BLOCKING THIS UPREGULATION PREVENTED NERVE INJURY-INDUCED DNA METHYLATION WITHIN THE PROMOTER AND 5'-UNTRANSLATED REGION OF KCNA2 GENE, RESCUED KCNA2 EXPRESSION AND TOTAL KV CURRENT, ATTENUATED HYPEREXCITABILITY IN THE INJURED DRG NEURONS, AND ALLEVIATED NERVE INJURY-INDUCED PAIN HYPERSENSITIVITIES. GIVEN THAT KCNA2 IS A KEY PLAYER IN NEUROPATHIC PAIN, OUR FINDINGS SUGGEST THAT DRG DNMT1 MAY BE A POTENTIAL TARGET FOR NEUROPATHIC PAIN MANAGEMENT.SIGNIFICANCE STATEMENT IN THE PRESENT STUDY, WE REPORTED THAT DNMT1, A CANONICAL DNA MAINTENANCE METHYLTRANSFERASE, IS UPREGULATED VIA THE ACTIVATION OF THE TRANSCRIPTION FACTOR CREB IN THE INJURED DRG AFTER PERIPHERAL NERVE INJURY. THIS UPREGULATION WAS RESPONSIBLE FOR NERVE INJURY-INDUCED DE NOVO DNA METHYLATION WITHIN THE PROMOTER AND 5'-UNTRANSLATED REGION OF THE KCNA2 GENE, REDUCTIONS IN KCNA2 EXPRESSION AND KV CURRENT AND INCREASES IN NEURONAL EXCITABILITY IN THE INJURED DRG. SINCE PHARMACOLOGICAL INHIBITION OR GENETIC KNOCKDOWN OF DRG DNMT1 ALLEVIATED NERVE INJURY-INDUCED PAIN HYPERSENSITIVITIES, DRG DNMT1 CONTRIBUTES TO NEUROPATHIC PAIN GENESIS PARTIALLY THROUGH REPRESSION OF DRG KCNA2 GENE EXPRESSION. 2019 3 6767 43 ZNF382 CONTROLS MOUSE NEUROPATHIC PAIN VIA SILENCER-BASED EPIGENETIC INHIBITION OF CXCL13 IN DRG NEURONS. NERVE INJURY-INDUCED CHANGES OF GENE EXPRESSION IN DORSAL ROOT GANGLION (DRG) ARE CRITICAL FOR NEUROPATHIC PAIN GENESIS. HOWEVER, HOW THESE CHANGES OCCUR REMAINS ELUSIVE. HERE WE REPORT THE DOWN-REGULATION OF ZINC FINGER PROTEIN 382 (ZNF382) IN INJURED DRG NEURONS AFTER NERVE INJURY. RESCUING THIS DOWN-REGULATION ATTENUATES NOCICEPTIVE HYPERSENSITIVITY. CONVERSELY, MIMICKING THIS DOWN-REGULATION PRODUCES NEUROPATHIC PAIN SYMPTOMS, WHICH ARE ALLEVIATED BY C-X-C MOTIF CHEMOKINE 13 (CXCL13) KNOCKDOWN OR ITS RECEPTOR CXCR5 KNOCKOUT. MECHANISTICALLY, AN IDENTIFIED CIS-ACTING SILENCER AT DISTAL UPSTREAM OF THE CXCL13 PROMOTER SUPPRESSES CXCL13 TRANSCRIPTION VIA BINDING TO ZNF382. BLOCKING THIS BINDING OR GENETICALLY DELETING THIS SILENCER ABOLISHES THE ZNF382 SUPPRESSION ON CXCL13 TRANSCRIPTION AND IMPAIRS ZNF382-INDUCED ANTINOCICEPTION. MOREOVER, ZNF382 DOWN-REGULATION DISRUPTS THE REPRESSIVE EPIGENETIC COMPLEX CONTAINING HISTONE DEACETYLASE 1 AND SET DOMAIN BIFURCATED 1 AT THE SILENCER-PROMOTER LOOP, RESULTING IN CXCL13 TRANSCRIPTIONAL ACTIVATION. THUS, ZNF382 DOWN-REGULATION IS REQUIRED FOR NEUROPATHIC PAIN LIKELY THROUGH SILENCER-BASED EPIGENETIC DISINHIBITION OF CXCL13, A KEY NEUROPATHIC PAIN PLAYER, IN DRG NEURONS. 2021 4 5574 48 ROLE OF MICRORNA-143 IN NERVE INJURY-INDUCED UPREGULATION OF DNMT3A EXPRESSION IN PRIMARY SENSORY NEURONS. PERIPHERAL NERVE INJURY INCREASED THE EXPRESSION OF THE DNA METHYLTRANSFERASE 3A (DNMT3A) MRNA AND ITS ENCODING DNMT3A PROTEIN IN INJURED DORSAL ROOT GANGLIA (DRG). THIS INCREASE IS CONSIDERED AS AN ENDOGENOUS INSTIGATOR IN NEUROPATHIC PAIN GENESIS THROUGH EPIGENETIC SILENCING OF PAIN-ASSOCIATED GENES (SUCH AS OPRM1) IN INJURED DRG. HOWEVER, HOW DRG DNMT3A IS INCREASED FOLLOWING PERIPHERAL NERVE INJURY IS STILL ELUSIVE. WE REPORTED HERE THAT PERIPHERAL NERVE INJURY CAUSED BY THE FIFTH SPINAL NERVE LIGATION (SNL) DOWNREGULATED MICRORNA (MIR)-143 EXPRESSION IN INJURED DRG. THIS DOWNREGULATION WAS REQUIRED FOR SNL-INDUCED DRG DNMT3A INCREASE AS RESCUING MIR-143 DOWNREGULATION THROUGH MICROINJECTION OF MIR-143 MIMICS INTO INJURED DRG BLOCKED THE SNL-INDUCED INCREASE IN DNMT3A AND RESTORED THE SNL-INDUCED DECREASES IN OPRM1 MRNA AND ITS ENCODING MU OPIOID RECEPTOR (MOR) IN INJURED DRG, IMPAIRED SPINAL CORD CENTRAL SENSITIZATION AND NEUROPATHIC PAIN, AND IMPROVED MORPHINE ANALGESIC EFFECTS FOLLOWING SNL. MIMICKING SNL-INDUCED DRG MIR-143 DOWNREGULATION THROUGH DRG MICROINJECTION OF MIR143 INHIBITORS IN NAIVE RATS INCREASED THE EXPRESSION OF DNMT3A AND REDUCED THE EXPRESSION OF OPRM1 MRNA AND MOR IN INJECTED DRG AND PRODUCED NEUROPATHIC PAIN-LIKE SYMPTOMS. THESE FINDINGS SUGGEST THAT MIR-143 IS A NEGATIVE REGULATOR IN DNMT3A EXPRESSION IN THE DRG UNDER NEUROPATHIC PAIN CONDITIONS AND MAY BE A POTENTIAL TARGET FOR THERAPEUTIC MANAGEMENT OF NEUROPATHIC PAIN. 2017 5 4699 27 NFATC2-DEPENDENT EPIGENETIC UPREGULATION OF CXCL14 IS INVOLVED IN THE DEVELOPMENT OF NEUROPATHIC PAIN INDUCED BY PACLITAXEL. BACKGROUND: THE MAJOR DOSE-LIMITING TOXICITY OF PACLITAXEL, ONE OF THE MOST COMMONLY USED DRUGS TO TREAT SOLID TUMOR, IS PAINFUL NEUROPATHY. HOWEVER, THE MOLECULAR MECHANISMS UNDERLYING PACLITAXEL-INDUCED PAINFUL NEUROPATHY ARE LARGELY UNCLARIFIED. METHODS: PAW WITHDRAWAL THRESHOLD WAS MEASURED IN THE RATS FOLLOWING INTRAPERITONEAL INJECTION OF PACLITAXEL. THE QPCR, WESTERN BLOTTING, PROTEIN OR CHROMATIN IMMUNOPRECIPITATION, CHIP-SEQ IDENTIFICATION OF NFATC2 BINDING SITES, AND MICROARRAY ANALYSIS WERE PERFORMED TO EXPLORE THE MOLECULAR MECHANISM. RESULTS: WE FOUND THAT PACLITAXEL TREATMENT INCREASED THE NUCLEAR EXPRESSION OF NFATC2 IN THE SPINAL DORSAL HORN, AND KNOCKDOWN OF NFATC2 WITH NFATC2 SIRNA SIGNIFICANTLY ATTENUATED THE MECHANICAL ALLODYNIA INDUCED BY PACLITAXEL. FURTHER BINDING SITE ANALYSIS UTILIZING CHIP-SEQ ASSAY COMBINING WITH GENE EXPRESSION PROFILE REVEALED A SHIFT OF NFATC2 BINDING SITE CLOSER TO TTS OF TARGET GENES IN DORSAL HORN AFTER PACLITAXEL TREATMENT. WE FURTHER FOUND THAT NFATC2 OCCUPANCY MAY DIRECTLY UPREGULATE THE CHEMOKINE CXCL14 EXPRESSION IN DORSAL HORN, WHICH WAS MEDIATED BY ENHANCED INTERACTION BETWEEN NFATC2 AND P300 AND CONSEQUENTLY INCREASED ACETYLATION OF HISTONE H4 IN CXCL14 PROMOTER REGION. ALSO, KNOCKDOWN OF CXCL14 IN DORSAL HORN SIGNIFICANTLY ATTENUATED MECHANICAL ALLODYNIA INDUCED BY PACLITAXEL. CONCLUSION: THESE RESULTS SUGGESTED THAT ENHANCED INTERACTION BETWEEN P300 AND NFATC2 MEDIATED THE EPIGENETIC UPREGULATION OF CXCL14 IN THE SPINAL DORSAL HORN, WHICH CONTRIBUTED TO THE CHEMOTHERAPEUTIC PACLITAXEL-INDUCED CHRONIC PAIN. 2020 6 1654 36 DORSAL ROOT GANGLIA COACTIVATOR-ASSOCIATED ARGININE METHYLTRANSFERASE 1 CONTRIBUTES TO PERIPHERAL NERVE INJURY-INDUCED PAIN HYPERSENSITIVITIES. NEUROPATHIC PAIN IS ASSOCIATED WITH GENE EXPRESSION CHANGES WITHIN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, WHICH INVOLVES EPIGENETIC MECHANISMS. COACTIVATOR-ASSOCIATED ARGININE METHYLTRANSFERASE 1 (CARM1), AN EPIGENETIC ACTIVATOR, REGULATES GENE TRANSCRIPTIONAL ACTIVITY BY PROTEIN POSTTRANSLATIONAL MODIFICATIONS. HOWEVER, WHETHER CARM1 PLAYS AN ESSENTIAL ROLE IN THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN IS UNKNOWN. WE REPORT HERE THAT PERIPHERAL NERVE INJURY INDUCED THE UPREGULATION OF THE MRNA AND PROTEIN EXPRESSION OF CARM1 IN THE INJURED DRG, AND BLOCKING ITS EXPRESSION THROUGH SMALL INTERFERING RNA (SIRNA) IN THE INJURED DRG ATTENUATED THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN. FURTHERMORE, PHARMACOLOGICAL INHIBITION OF CARM1 MITIGATED PERIPHERAL NERVE INJURY-INDUCED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA. GIVEN THAT CARM1 INHIBITION OR KNOCKDOWN ATTENUATED THE INDUCTION AND MAINTENANCE OF NEUROPATHIC PAIN AFTER PERIPHERAL NERVE INJURY, OUR FINDINGS SUGGEST THAT CARM1 MAY SERVE AS A PROMISING THERAPEUTIC TARGET FOR NEUROPATHIC PAIN TREATMENT IN CLINICAL APPLICATIONS. 2018 7 4366 29 MIRNA-23A/CXCR4 REGULATES NEUROPATHIC PAIN VIA DIRECTLY TARGETING TXNIP/NLRP3 INFLAMMASOME AXIS. BACKGROUND: CHEMOKINE CXC RECEPTOR 4 (CXCR4) IN SPINAL GLIAL CELLS HAS BEEN IMPLICATED IN NEUROPATHIC PAIN. HOWEVER, THE REGULATORY CASCADES OF CXCR4 IN NEUROPATHIC PAIN REMAIN ELUSIVE. HERE, WE INVESTIGATED THE FUNCTIONAL REGULATORY ROLE OF MIRNAS IN THE PAIN PROCESS AND ITS INTERPLAY WITH CXCR4 AND ITS DOWNSTREAM SIGNALING. METHODS: MIRNAS AND CXCR4 AND ITS DOWNSTREAM SIGNALING MOLECULES WERE MEASURED IN THE SPINAL CORDS OF MICE WITH SCIATIC NERVE INJURY VIA PARTIAL SCIATIC NERVE LIGATION (PSNL). IMMUNOBLOTTING, IMMUNOFLUORESCENCE, IMMUNOPRECIPITATION, AND MAMMAL TWO-HYBRID AND BEHAVIORAL TESTS WERE USED TO EXPLORE THE DOWNSTREAM CXCR4-DEPENDENT SIGNALING PATHWAY. RESULTS: CXCR4 EXPRESSION INCREASED IN SPINAL GLIAL CELLS OF MICE WITH PSNL-INDUCED NEUROPATHIC PAIN. BLOCKING CXCR4 ALLEVIATED THE PAIN BEHAVIOR; CONTRARILY, OVEREXPRESSING CXCR4 INDUCED PAIN HYPERSENSITIVITY. MICRORNA-23A-3P (MIR-23A) DIRECTLY BOUNDS TO 3' UTR OF CXCR4 MRNA. PSNL-INDUCED NEUROPATHIC PAIN SIGNIFICANTLY REDUCED MRNA EXPRESSION OF MIR-23A. OVEREXPRESSION OF MIR-23A BY INTRATHECAL INJECTION OF MIR-23A MIMICS OR LENTIVIRUS REDUCED SPINAL CXCR4 AND PREVENTED PSNL-INDUCED NEUROPATHIC PAIN. IN CONTRAST, KNOCKDOWN OF MIR-23A BY INTRATHECAL INJECTION OF MIR-23A INHIBITOR OR LENTIVIRUS INDUCED PAIN-LIKE BEHAVIOR, WHICH WAS REDUCED BY CXCR4 INHIBITION. ADDITIONALLY, MIR-23A KNOCKDOWN OR CXCR4 OVEREXPRESSION IN NAIVE MICE COULD INCREASE THE THIOREDOXIN-INTERACTING PROTEIN (TXNIP), WHICH WAS ASSOCIATED WITH INDUCTION OF NOD-LIKE RECEPTOR PROTEIN 3 (NLRP3) INFLAMMASOME. INDEED, CXCR4 AND TXNIP WERE CO-EXPRESSED. THE MAMMAL TWO-HYBRID ASSAY REVEALED THE DIRECT INTERACTION BETWEEN CXCR4 AND TXNIP, WHICH WAS INCREASED IN THE SPINAL CORD OF PSNL MICE. IN PARTICULAR, INHIBITION OF TXNIP REVERSED PAIN BEHAVIOR ELICITED BY PSNL, MIR-23A KNOCKDOWN, OR CXCR4 OVEREXPRESSION. MOREOVER, MIR-23A OVEREXPRESSION OR CXCR4 KNOCKDOWN INHIBITED THE INCREASE OF TXNIP AND NLRP3 INFLAMMASOME IN PSNL MICE. CONCLUSIONS: MIR-23A, BY DIRECTLY TARGETING CXCR4, REGULATES NEUROPATHIC PAIN VIA TXNIP/NLRP3 INFLAMMASOME AXIS IN SPINAL GLIAL CELLS. EPIGENETIC INTERVENTIONS AGAINST MIR-23A, CXCR4, OR TXNIP MAY POTENTIALLY SERVE AS NOVEL THERAPEUTIC AVENUES IN TREATING PERIPHERAL NERVE INJURY-INDUCED NOCICEPTIVE HYPERSENSITIVITY. 2018 8 4160 44 MECP2 EPIGENETIC SILENCING OF OPRM1 GENE IN PRIMARY SENSORY NEURONS UNDER NEUROPATHIC PAIN CONDITIONS. OPIOIDS ARE THE LAST OPTION FOR THE PHARMACOLOGICAL TREATMENT OF NEUROPATHIC PAIN, BUT THEIR ANTINOCICEPTIVE EFFECTS ARE LIMITED. DECREASED MU OPIOID RECEPTOR (MOR) EXPRESSION IN THE PERIPHERAL NERVOUS SYSTEM MAY CONTRIBUTE TO THIS. HERE, WE SHOWED THAT NERVE INJURY INDUCED HYPERMETHYLATION OF THE OPRM1 GENE PROMOTER AND AN INCREASED EXPRESSION OF METHYL-CPG BINDING PROTEIN 2 (MECP2) IN INJURED DORSAL ROOT GANGLION (DRG). THE DOWNREGULATION OF MOR IN THE DRG IS CLOSELY RELATED TO THE AUGMENTATION OF MECP2, AN EPIGENETIC REPRESSOR, WHICH COULD RECRUIT HDAC1 AND BIND TO THE METHYLATED REGIONS OF THE OPRM1 GENE PROMOTER. MECP2 KNOCKDOWN RESTORED THE EXPRESSION OF MOR IN INJURED DRG AND ENHANCED THE ANALGESIC EFFECT OF MORPHINE, WHILE THE MIMICKING OF THIS INCREASE VIA THE INTRATHECAL INFUSION OF VIRAL VECTOR-MEDIATED MECP2 WAS SUFFICIENT TO REDUCE MOR IN THE DRG. MOREOVER, HDAC1 INHIBITION WITH SUBEROYLANILIDE HYDROXAMIC ACID, AN HDAC INHIBITOR, ALSO PREVENTED MOR REDUCTION IN THE DRG OF NEUROPATHIC PAIN MICE, CONTRIBUTING TO THE AUGMENTATION OF MORPHINE ANALGESIA EFFECTS. MECHANISTICALLY, UPREGULATED MECP2 PROMOTES THE BINDING OF A HIGH LEVEL OF HDCA1 TO HYPERMETHYLATED REGIONS OF THE OPRM1 GENE PROMOTER, REDUCES THE ACETYLATION OF HISTONE H3 (ACH3) LEVELS OF THE OPRM1 GENE PROMOTER, AND ATTENUATES OPRM1 TRANSCRIPTION IN INJURED DRG. THUS, UPREGULATED MECP2 AND HDAC1 IN OPRM1 GENE PROMOTER SITES, NEGATIVELY REGULATES MOR EXPRESSION IN INJURED DRG, MITIGATING THE ANALGESIC EFFECT OF THE OPIOIDS. TARGETING MECP2/HDAC1 MAY THUS PROVIDE A NEW SOLUTION FOR IMPROVING THE THERAPEUTIC EFFECT OF OPIOIDS IN A CLINICAL SETTING. 2021 9 5266 38 PROMOTED INTERACTION OF C/EBPALPHA WITH DEMETHYLATED CXCR3 GENE PROMOTER CONTRIBUTES TO NEUROPATHIC PAIN IN MICE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER NEUROPATHIC PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR3 IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY SPINAL NERVE LIGATION (SNL) IN MICE. SNL INCREASED CXCR3 MRNA AND PROTEIN EXPRESSION IN THE NEURONS OF THE SPINAL CORD. MEANWHILE, THE CPG (5'-CYTOSINE-PHOSPHATE-GUANINE-3') ISLAND IN THE CXCR3 GENE PROMOTER REGION WAS DEMETHYLATED, AND THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) WAS DECREASED. SNL ALSO INCREASED THE BINDING OF CCAAT (CYTIDINE-CYTIDINE-ADENOSINE-ADENOSINE-THYMIDINE)/ENHANCER BINDING PROTEIN ALPHA (C/EBPALPHA) WITH CXCR3 PROMOTER AND DECREASED THE BINDING OF DNMT3B WITH CXCR3 PROMOTER IN THE SPINAL CORD. C/EBPALPHA EXPRESSION WAS INCREASED IN SPINAL NEURONS AFTER SNL, AND INHIBITION OF C/EBPALPHA BY INTRATHECAL SMALL INTERFERING RNA ATTENUATED SNL-INDUCED PAIN HYPERSENSITIVITY AND REDUCED CXCR3 EXPRESSION. FURTHERMORE, SNL-INDUCED MECHANICAL ALLODYNIA AND HEAT HYPERALGESIA WERE MARKEDLY REDUCED IN CXCR3(-/-) MICE. SPINAL INHIBITION OF CXCR3 BY SHRNA OR CXCR3 ANTAGONIST ALSO ATTENUATED ESTABLISHED NEUROPATHIC PAIN. MOREOVER, CXCL10, THE LIGAND OF CXCR3, WAS INCREASED IN SPINAL NEURONS AND ASTROCYTES AFTER SNL. SUPERFUSING SPINAL CORD SLICES WITH CXCL10 ENHANCED SPONTANEOUS EPSCS AND POTENTIATED NMDA-INDUCED AND AMPA-INDUCED CURRENTS OF LAMINA II NEURONS. FINALLY, INTRATHECAL INJECTION OF CXCL10 INDUCED CXCR3-DEPENDENT PAIN HYPERSENSITIVITY IN NAIVE MICE. COLLECTIVELY, OUR RESULTS DEMONSTRATED THAT CXCR3, INCREASED BY DNA DEMETHYLATION AND THE ENHANCED INTERACTION WITH C/EBPALPHA, CAN BE ACTIVATED BY CXCL10 TO FACILITATE EXCITATORY SYNAPTIC TRANSMISSION AND CONTRIBUTE TO THE MAINTENANCE OF NEUROPATHIC PAIN. SIGNIFICANCE STATEMENT: PERIPHERAL NERVE INJURY INDUCES CHANGES OF GENE EXPRESSION IN THE SPINAL CORD THAT MAY CONTRIBUTE TO THE PATHOGENESIS OF NEUROPATHIC PAIN. CXCR3 IS A CHEMOKINE RECEPTOR. WHETHER IT IS INVOLVED IN NEUROPATHIC PAIN AND HOW IT IS REGULATED AFTER NERVE INJURY REMAIN LARGELY UNKNOWN. OUR STUDY DEMONSTRATES THAT SPINAL NERVE LIGATION DOWNREGULATES THE EXPRESSION OF DNMT3B, WHICH MAY CAUSE DEMETHYLATION OF CXCR3 GENE PROMOTER AND FACILITATE THE BINDING OF CCAAT/ENHANCER BINDING PROTEIN ALPHA WITH CXCR3 PROMOTER AND FURTHER INCREASE CXCR3 EXPRESSION IN SPINAL NEURONS. THE UPREGULATED CXCR3 MAY CONTRIBUTE TO NEUROPATHIC PAIN BY FACILITATING CENTRAL SENSITIZATION. OUR STUDY REVEALS AN EPIGENETIC MECHANISM UNDERLYING CXCR3 EXPRESSION AND ALSO SUGGESTS THAT TARGETING THE EXPRESSION OR ACTIVATION OF CXCR3 SIGNALING MAY OFFER NEW THERAPEUTICS FOR NEUROPATHIC PAIN. 2017 10 2884 42 G9A IS ESSENTIAL FOR EPIGENETIC SILENCING OF K(+) CHANNEL GENES IN ACUTE-TO-CHRONIC PAIN TRANSITION. NEUROPATHIC PAIN IS A DEBILITATING CLINICAL PROBLEM AND DIFFICULT TO TREAT. NERVE INJURY CAUSES A LONG-LASTING REDUCTION IN K(+) CHANNEL EXPRESSION IN THE DORSAL ROOT GANGLION (DRG), BUT LITTLE IS KNOWN ABOUT THE EPIGENETIC MECHANISMS INVOLVED. WE FOUND THAT NERVE INJURY INCREASED DIMETHYLATION OF LYS9 ON HISTONE H3 (H3K9ME2) AT KCNA4, KCND2, KCNQ2 AND KCNMA1 PROMOTERS BUT DID NOT AFFECT LEVELS OF DNA METHYLATION ON THESE GENES IN DRGS. NERVE INJURY INCREASED ACTIVITY OF EUCHROMATIC HISTONE-LYSINE N-METHYLTRANSFERASE-2 (G9A), HISTONE DEACETYLASES AND ENHANCER OF ZESTE HOMOLOG-2 (EZH2), BUT ONLY G9A INHIBITION CONSISTENTLY RESTORED K(+) CHANNEL EXPRESSION. SELECTIVE KNOCKOUT OF THE GENE ENCODING G9A IN DRG NEURONS COMPLETELY BLOCKED K(+) CHANNEL SILENCING AND CHRONIC PAIN DEVELOPMENT AFTER NERVE INJURY. REMARKABLY, RNA SEQUENCING ANALYSIS REVEALED THAT G9A INHIBITION NOT ONLY REACTIVATED 40 OF 42 SILENCED GENES ASSOCIATED WITH K(+) CHANNELS BUT ALSO NORMALIZED 638 GENES DOWN- OR UPREGULATED BY NERVE INJURY. THUS G9A HAS A DOMINANT FUNCTION IN TRANSCRIPTIONAL REPRESSION OF K(+) CHANNELS AND IN ACUTE-TO-CHRONIC PAIN TRANSITION AFTER NERVE INJURY. 2015 11 2407 39 EPIGENETIC RESTORATION OF VOLTAGE-GATED POTASSIUM CHANNEL KV1.2 ALLEVIATES NERVE INJURY-INDUCED NEUROPATHIC PAIN. VOLTAGE-GATED POTASSIUM CHANNELS (KV) ARE IMPORTANT REGULATORS OF NEURONAL EXCITABILITY FOR ITS ROLE OF REGULATING RESTING MEMBRANE POTENTIAL AND REPOLARIZATION. RECENT STUDIES SHOW THAT KV CHANNELS PARTICIPATE IN NEUROPATHIC PAIN, BUT THE DETAILED UNDERLYING MECHANISMS ARE FAR FROM BEING CLEAR. IN THIS STUDY, WE USED SIRNA, MIR-137 AGOMIR, AND ANTAGOMIR TO REGULATE THE EXPRESSION OF KV1.2 IN SPINAL CORD AND DORSAL ROOT GANGLIA (DRG) OF NAIVE AND CHRONIC CONSTRICTION INJURY (CCI) RATS. KV CURRENTS AND NEURON EXCITABILITY IN DRG NEURONS WERE EXAMINED BY PATCH-CLAMP WHOLE-CELL RECORDING TO VERIFY THE CHANGE IN KV1.2 FUNCTION. THE RESULTS SHOWED THAT KV1.2 WAS DOWN-REGULATED IN DRG AND SPINAL DORSAL HORN (SDH) BY CCI. KNOCKDOWN OF KV1.2 BY INTRATHECALLY INJECTING KCNA2 SIRNA INDUCED SIGNIFICANT MECHANICAL AND THERMAL HYPERSENSITIVITY IN NAIVE RATS. CONCOMITANT WITH THE DOWN-REGULATION OF KV1.2 WAS AN INCREASE IN THE EXPRESSION OF THE MIR-137. THE TARGETING AND REGULATING OF MIR-137 ON KCNA2 WAS VERIFIED BY DUAL-LUCIFERASE REPORTER SYSTEM AND INTRATHECAL INJECTING MIR-137 AGOMIR. FURTHERMORE, RESCUING THE EXPRESSION OF KV1.2 IN CCI RATS, ACHIEVED THROUGH INHIBITING MIR-137, RESTORED THE ABNORMAL KV CURRENTS AND EXCITABILITY IN DRG NEURONS, AND ALLEVIATED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA. THESE RESULTS INDICATE THAT THE MIR-137-MEDIATED KV1.2 IMPAIRMENT IS A CRUCIAL ETIOPATHOGENESIS FOR THE NERVE INJURY-INDUCED NEUROPATHIC PAIN AND CAN BE A NOVEL POTENTIAL THERAPEUTIC TARGET FOR NEUROPATHIC PAIN MANAGEMENT. 2021 12 4615 47 NERVE INJURY DIMINISHES OPIOID ANALGESIA THROUGH LYSINE METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL REPRESSION OF MU-OPIOID RECEPTORS IN PRIMARY SENSORY NEURONS. THE MU-OPIOID RECEPTOR (MOR, ENCODED BY OPRM1) AGONISTS ARE THE MAINSTAY ANALGESICS FOR TREATING MODERATE TO SEVERE PAIN. NERVE INJURY CAUSES DOWN-REGULATION OF MORS IN THE DORSAL ROOT GANGLION (DRG) AND DIMINISHES THE OPIOID EFFECT ON NEUROPATHIC PAIN. HOWEVER, THE EPIGENETIC MECHANISMS UNDERLYING THE DIMINISHED MOR EXPRESSION CAUSED BY NERVE INJURY ARE NOT CLEAR. G9A (ENCODED BY EHMT2), A HISTONE 3 AT LYSINE 9 METHYLTRANSFERASE, IS A KEY CHROMATIN REGULATOR RESPONSIBLE FOR GENE SILENCING. IN THIS STUDY, WE DETERMINED THE ROLE OF G9A IN DIMINISHED MOR EXPRESSION AND OPIOID ANALGESIC EFFECTS IN ANIMAL MODELS OF NEUROPATHIC PAIN. WE FOUND THAT NERVE INJURY IN RATS INDUCED A LONG-LASTING REDUCTION IN THE EXPRESSION LEVEL OF MORS IN THE DRG BUT NOT IN THE SPINAL CORD. NERVE INJURY CONSISTENTLY INCREASED THE ENRICHMENT OF THE G9A PRODUCT HISTONE 3 AT LYSINE 9 DIMETHYLATION IN THE PROMOTER OF OPRM1 IN THE DRG. G9A INHIBITION OR SIRNA KNOCKDOWN FULLY REVERSED MOR EXPRESSION IN THE INJURED DRG AND POTENTIATED THE MORPHINE EFFECT ON PAIN HYPERSENSITIVITY INDUCED BY NERVE INJURY. IN MICE LACKING EHMT2 IN DRG NEURONS, NERVE INJURY FAILED TO REDUCE THE EXPRESSION LEVEL OF MORS AND THE MORPHINE EFFECT. IN ADDITION, G9A INHIBITION OR EHMT2 KNOCKOUT IN DRG NEURONS NORMALIZED NERVE INJURY-INDUCED REDUCTION IN THE INHIBITORY EFFECT OF THE OPIOID ON SYNAPTIC GLUTAMATE RELEASE FROM PRIMARY AFFERENT NERVES. OUR FINDINGS INDICATE THAT G9A CONTRIBUTES CRITICALLY TO TRANSCRIPTIONAL REPRESSION OF MORS IN PRIMARY SENSORY NEURONS IN NEUROPATHIC PAIN. G9A INHIBITORS MAY BE USED TO ENHANCE THE OPIOID ANALGESIC EFFECT IN THE TREATMENT OF CHRONIC NEUROPATHIC PAIN. 2016 13 2272 32 EPIGENETIC REDUCTION OF MIR-214-3P UPREGULATES ASTROCYTIC COLONY-STIMULATING FACTOR-1 AND CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY NERVE INJURY. EMERGING EVIDENCE HAS INDICATED THAT COLONY-STIMULATING FACTOR-1 (CSF1) MODULATES NEUROINFLAMMATION IN THE CENTRAL NERVOUS SYSTEM AND THE DEVELOPMENT OF NEUROPATHIC PAIN, WHILE THE UNDERLYING MECHANISM REMAINS UNKNOWN. HERE, WE IDENTIFIED THE INCREASED EXPRESSION OF CSF1 DERIVED FROM ACTIVATED ASTROCYTES IN THE IPSILATERAL DORSAL HORN IN RATS WITH SPINAL NERVE LIGATION (SNL). SUPPRESSION OF CSF1 EXPRESSION ALLEVIATED NEUROINFLAMMATION, NEURONAL HYPEREXCITABILITY, AND GLUTAMATERGIC RECEPTOR SUBUNIT UPREGULATION IN THE DORSAL HORN AND IMPROVED SNL-INDUCED PAIN BEHAVIOR. WE ALSO FOUND REDUCED MIR-214-3P EXPRESSION IN THE IPSILATERAL DORSAL HORN FOLLOWING AN SNL PROCEDURE; MIR-214-3P DIRECTLY BOUND TO THE 3'-UTR OF CSF1 MRNA AND NEGATIVELY REGULATED CSF1 EXPRESSION. INTRATHECAL DELIVERY OF MIR-214-3P MIMIC REVERSED THE ENHANCED EXPRESSION OF CSF1 AND ASTROCYTE OVERACTIVITY AND ALLEVIATED THE IL-6 UPREGULATION AND PAIN BEHAVIOR INDUCED BY SNL. MOREOVER, SUPPRESSION OF SPINAL MIR-214-3P INCREASED ASTROCYTE REACTIVITY, PROMOTED CSF1 AND IL-6 PRODUCTION, AND INDUCED PAIN HYPERSENSITIVITY IN NAIVE ANIMALS. FURTHERMORE, SNL INDUCED THE EXPRESSION OF DNA METHYLTRANSFERASE 3A (DNMT3A) THAT WAS ASSOCIATED WITH THE HYPERMETHYLATION OF THE MIR-214-3P PROMOTER, LEADING TO REDUCED MIR-214-3P EXPRESSION IN THE MODEL RODENTS. TREATMENT WITH THE DNMT INHIBITOR ZEBULARINE SIGNIFICANTLY REDUCED CYTOSINE METHYLATION IN THE MIR-214-3P PROMOTER; THIS REDUCED METHYLATION CONSEQUENTLY INCREASED THE EXPRESSION OF MIR-214-3P AND DECREASED THE CONTENT OF CSF1 IN THE IPSILATERAL DORSAL HORN AND, FURTHER, ATTENUATED IL-6 PRODUCTION AND PAIN BEHAVIOR IN RATS WITH SNL. TOGETHER, OUR DATA INDICATE THAT THE DNMT3A-MEDIATED EPIGENETIC SUPPRESSION OF MIR-214-3P ENHANCED CSF1 PRODUCTION IN ASTROCYTES, WHICH SUBSEQUENTLY INDUCED NEUROINFLAMMATION AND PAIN BEHAVIOR IN SNL MODEL RATS. 2020 14 1630 42 DNMT3A CONTRIBUTES TO THE DEVELOPMENT AND MAINTENANCE OF BONE CANCER PAIN BY SILENCING KV1.2 EXPRESSION IN SPINAL CORD DORSAL HORN. METASTATIC BONE TUMOR-INDUCED CHANGES IN GENE TRANSCRIPTION AND TRANSLATION IN PAIN-RELATED REGIONS OF THE NERVOUS SYSTEM MAY PARTICIPATE IN THE DEVELOPMENT AND MAINTENANCE OF BONE CANCER PAIN. EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION REGULATE GENE TRANSCRIPTION. HERE, WE REPORT THAT INTRATHECAL INJECTION OF DECITABINE, A DNA METHYLTRANSFERASE (DNMT) INHIBITOR, DOSE DEPENDENTLY ATTENUATED THE DEVELOPMENT AND MAINTENANCE OF BONE CANCER PAIN INDUCED BY INJECTING PROSTATE CANCER CELLS INTO THE TIBIA. THE LEVEL OF THE DE NOVO DNMT3A, BUT NOT DNMT3B, TIME DEPENDENTLY INCREASED IN THE IPSILATERAL L4/5 DORSAL HORN (NOT L4/5 DORSAL ROOT GANGLION) AFTER PROSTATE CANCER CELLS INJECTION. BLOCKING THIS INCREASE THROUGH MICROINJECTION OF RECOMBINANT ADENO-ASSOCIATED VIRUS 5 (AAV5) EXPRESSING DNMT3A SHRNA INTO DORSAL HORN RESCUED PROSTATE CANCER CELLS-INDUCED DOWNREGULATION OF DORSAL HORN KV1.2 EXPRESSION AND IMPAIRED PROSTATE CANCER CELLS-INDUCED PAIN HYPERSENSITIVITY. IN TURN, MIMICKING THIS INCREASE THROUGH MICROINJECTION OF AAV5 EXPRESSING FULL-LENGTH DNMT3A INTO DORSAL HORN REDUCED DORSAL HORN KV1.2 EXPRESSION AND PRODUCED PAIN HYPERSENSITIVITY IN THE ABSENCE OF PROSTATE CANCER CELLS INJECTION. ADMINISTRATION OF NEITHER DECITABINE NOR VIRUS AFFECTED LOCOMOTOR FUNCTION AND ACUTE RESPONSES TO MECHANICAL, THERMAL, OR COLD STIMULI. GIVEN THAT DNMT3A MRNA IS CO-EXPRESSED WITH KCNA2 MRNA (ENCODING KV1.2) IN INDIVIDUAL DORSAL HORN NEURONS, OUR FINDINGS SUGGEST THAT INCREASED DORSAL HORN DNMT3A CONTRIBUTES TO BONE CANCER PAIN THROUGH SILENCING DORSAL HORN KV1.2 EXPRESSION. DNMT3A MAY REPRESENT A POTENTIAL NEW TARGET FOR CANCER PAIN MANAGEMENT. 2017 15 3832 24 INVOLVEMENT OF SPINAL SIRT1 IN DEVELOPMENT OF CHRONIC CONSTRICTION INJURY INDUCED NEUROPATHIC PAIN IN RATS. IT IS KNOWN THAT THE EPIGENETIC PROCESS OF HISTONE ACETYLATION IS INVOLVED IN THE NEUROPATHIC PAIN. THE AIM OF THIS STUDY WAS TO DETERMINE WHETHER SIRTUIN TYPE 1 (SIRT1), AN NAD(+) DEPENDENT DEACETYLASE, AFFECTED ALLODYNIA AND HYPERALGESIA IN NEUROPATHIC PAIN. THE NEUROPATHIC PAIN MODEL WAS ESTABLISHED BY LIGATURE OF THE RIGHT SCIATIC NERVE TO INDUCE CHRONIC CONSTRICTION INJURY (CCI) IN RATS. HISTONE ACETYLTRANSFERASE (HAT) ACTIVITY WAS INCREASED AND, AND HISTONE DEACETYLASE (HDAC) ACTIVITY WAS DECLINED IN TISSUE OF THE SPINAL DORSA HORN IN CCI RATES BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA). THE PERSISTENT HYPERALGESIA AND ALLODYNIA CAUSED BY CCI WERE ASSOCIATED WITH DOWNREGULATION OF SIRT1 AND UPREGULATION OF ACETYLATED-H3 (AC-H3) IN TISSUE OF THE SPINAL CORD BY WESTERN BLOT ASSAY, WHICH WAS REVERSED AFTER INTRATHECAL INJECTION OF SIRT1 AGONIST SRT1720. SRT1720 TREATMENT ACHIEVED ANALGESIC THROUGH INHIBITING THE ACETYLATION OF NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND BLOCKING THE RELEASES OF THE INFLAMMATORY FACTORS INCLUDING TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) AND INTERLEUKIN (IL)-6 BY MEANS OF WESTERN BLOT AND REAL-TIME QUANTITATIVE PCR (RT-PCR), RESPECTIVELY. TAKEN TOGETHER, THESE DATA SUGGEST THAT SIRT1 IN THE SPINAL CORD PLAYS AN IMPORTANT ROLE IN THE NEUROPATHIC PAIN IN THE RAT MODEL. 2018 16 717 33 CALCITONIN GENE-RELATED PEPTIDE REGULATES SPINAL MICROGLIAL ACTIVATION THROUGH THE HISTONE H3 LYSINE 27 TRIMETHYLATION VIA ENHANCER OF ZESTE HOMOLOG-2 IN RATS WITH NEUROPATHIC PAIN. BACKGROUND: CALCITONIN GENE-RELATED PEPTIDE (CGRP) AS A MEDIATOR OF MICROGLIAL ACTIVATION AT THE TRANSCRIPTIONAL LEVEL MAY FACILITATE NOCICEPTIVE SIGNALING. TRIMETHYLATION OF H3 LYSINE 27 (H3K27ME3) BY ENHANCER OF ZESTE HOMOLOG 2 (EZH2) IS AN EPIGENETIC MARK THAT REGULATES INFLAMMATORY-RELATED GENE EXPRESSION AFTER PERIPHERAL NERVE INJURY. IN THIS STUDY, WE EXPLORED THE RELATIONSHIP BETWEEN CGRP AND H3K27ME3 IN MICROGLIAL ACTIVATION AFTER NERVE INJURY, AND ELUCIDATED THE UNDERLYING MECHANISMS IN THE PATHOGENESIS OF CHRONIC NEUROPATHIC PAIN. METHODS: MICROGLIAL CELLS (BV2) WERE TREATED WITH CGRP AND DIFFERENTIALLY ENRICHMENTS OF H3K27ME3 ON GENE PROMOTERS WERE EXAMINED USING CHIP-SEQ. A CHRONIC CONSTRICTION INJURY (CCI) RAT MODEL WAS USED TO EVALUATE THE ROLE OF CGRP ON MICROGLIAL ACTIVATION AND EZH2/H3K27ME3 SIGNALING IN CCI-INDUCED NEUROPATHIC PAIN. RESULTS: OVEREXPRESSIONS OF EZH2 AND H3K27ME3 WERE CONFIRMED IN SPINAL MICROGLIA OF CCI RATS BY IMMUNOFLUORESCENCE. CGRP TREATMENT INDUCED THE INCREASED OF H3K27ME3 EXPRESSION IN THE SPINAL DORSAL HORN AND CULTURED MICROGLIAL CELLS (BV2) THROUGH EZH2. CHIP-SEQ DATA INDICATED THAT CGRP SIGNIFICANTLY ALTERED H3K27ME3 ENRICHMENTS ON GENE PROMOTERS IN MICROGLIA FOLLOWING CGRP TREATMENT, INCLUDING 173 GAINING H3K27ME3 AND 75 LOSING THIS MARK, WHICH MOSTLY ENRICHED IN REGULATION OF CELL GROWTH, PHAGOSOME, AND INFLAMMATION. QRT-PCR VERIFIED EXPRESSIONS OF REPRESENTATIVE CANDIDATE GENES (TRAF3IP2, BCL2L11, ITGAM, DAB2, NLRP12, WNT3, ADAM10) AND REAL-TIME CELL ANALYSIS (RTCA) VERIFIED MICROGLIAL PROLIFERATION. ADDITIONALLY, CGRP TREATMENT AND CCI INCREASED EXPRESSIONS OF ITGAM, ADAM10, MCP-1, AND CX3CR1, KEY MEDIATORS OF MICROGLIAL ACTIVATION IN SPINAL DORSAL HORN AND CULTURED MICROGLIAL CELLS. SUCH INCREASED EFFECTS INDUCED BY CCI WERE SUPPRESSED BY CGRP ANTAGONIST AND EZH2 INHIBITOR, WHICH WERE CONCURRENTLY ASSOCIATED WITH THE ATTENUATED MECHANICAL AND THERMAL HYPERALGESIA IN CCI RATS. CONCLUSION: OUR FINDINGS HIGHLY INDICATE THAT CGRP IS IMPLICATED IN THE GENESIS OF NEUROPATHIC PAIN THROUGH REGULATING MICROGLIAL ACTIVATION VIA EZH2-MEDIATED H3K27ME3 IN THE SPINAL DORSAL HORN. 2021 17 5976 29 TET1-DEPENDENT EPIGENETIC MODIFICATION OF BDNF EXPRESSION IN DORSAL HORN NEURONS MEDIATES NEUROPATHIC PAIN IN RATS. TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1) MEDIATES THE CONVERSION OF 5-METHYLCYTOSINE (5 MC) TO 5-HYDROXYMETHYLCYTOSINE (5 HMC), HENCE PROMOTING DNA DEMETHYLATION. ALTHOUGH RECENT STUDIES HAVE LINKED THE DNA DEMETHYLATION OF SPECIFIC GENES TO PAIN HYPERSENSITIVITY, THE ROLE OF SPINAL TET1-DEPENDENT DNA DEMETHYLATION IN NOCICEPTION HYPERSENSITIVITY DEVELOPMENT REMAINS ELUSIVE. HERE, WE REPORT CORRELATED WITH BEHAVIORAL ALLODYNIA, SPINAL NERVE LIGATION (SNL) UPREGULATED TET1 EXPRESSION IN DORSAL HORN NEURONS THAT HYDROXYLATE 5 MC TO 5 HMC AT CPG DINUCLEOTIDES IN THE BDNF PROMOTER TO PROMOTE SPINAL BDNF EXPRESSION AT DAY 7 AFTER OPERATION. FOCAL KNOCKDOWN OF SPINAL TET1 EXPRESSION DECREASED TET1 BINDING AND 5 HMC ENRICHMENT, FURTHER INCREASED 5 MC ENRICHMENT AT CPG SITES IN THE BDNF PROMOTER AND DECREASED SPINAL BDNF EXPRESSION ACCOMPANIED BY THE ALLEVIATION OF THE DEVELOPED ALLODYNIA. MOREOVER, AT DAY 7 AFTER OPERATION, SNL-ENHANCED TET1 EXPRESSION ALSO INHIBITED THE BINDING OF DNA METHYLTRANSFERASES (DNMTS, I.E., DNMT1, DNMT3A, AND DNMT3B) TO THE BDNF PROMOTER, A REQUIREMENT FOR TRANSCRIPTIONAL SILENCING BY CATALYSING 5-CYTOSINE (5C) TO 5 MC. TOGETHER, THESE DATA SUGGEST AT CPG SITES OF THE BDNF PROMOTER, SNL-ENHANCED TET1 EXPRESSION PROMOTES DNA DEMETHYLATION BOTH BY CONVERTING 5 MC TO 5 HMC AND INHIBITING DNMT BINDING TO REGULATE SPINAL BDNF EXPRESSION, HENCE CONTRIBUTING TO BEHAVIORAL ALLODYNIA DEVELOPMENT. 2016 18 2326 25 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 19 2479 28 EPIGENETIC UPREGULATION OF CXCL12 EXPRESSION MEDIATES ANTITUBULIN CHEMOTHERAPEUTICS-INDUCED NEUROPATHIC PAIN. CLINICALLY, MICROTUBULE-TARGETED AGENTS-INDUCED NEUROPATHIC PAIN HAMPERS CHEMOTHERAPEUTICS FOR PATIENTS WITH CANCER. HERE, WE FOUND THAT APPLICATION OF PACLITAXEL OR VINCRISTINE INCREASED THE PROTEIN AND MRNA EXPRESSION OF CXCL12 AND FREQUENCY AND AMPLITUDE OF MINIATURE EXCITATORY POST SYNAPTIC CURRENTS (MEPSCS) IN SPINAL DORSAL HORN NEURONS. SPINAL LOCAL APPLICATION OF CXCL12 INDUCED THE LONG-TERM POTENTIATION OF NOCICEPTIVE SYNAPTIC TRANSMISSION AND INCREASED THE AMPLITUDE OF MEPSCS. INHIBITION OF CXCL12 USING THE TRANSGENIC MICE (CXCL12) OR NEUTRALIZING ANTIBODY OR SIRNA AMELIORATED THE MEPSC'S ENHANCEMENT AND MECHANICAL ALLODYNIA. IN ADDITION, PACLITAXEL AND VINCRISTINE BOTH COULD INCREASE THE PHOSPHORYLATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) AND THE ACETYLATION OF HISTONE H4 IN THE CXCL12-EXPRESSING NEURONS. IMMUNOPRECIPITATION AND CHROMATIN IMMUNOPRECIPITATION ASSAYS DEMONSTRATED THAT ANTITUBULIN CHEMOTHERAPEUTICS INCREASED THE BINDING OF STAT3 TO THE CXCL12 GENE PROMOTER AND THE INTERACTION BETWEEN STAT3 AND P300, AND CONTRIBUTED TO THE ENHANCED TRANSCRIPTION OF CXCL12 BY INCREASING THE ACETYLATION OF HISTONE H4 IN CXCL12 GENE PROMOTER. INHIBITION OF STAT3 BY INTRATHECAL INJECTION OF ADENO-ASSOCIATED VIRUS ENCODING CRE AND GREEN FLUORESCENT PROTEIN INTO STAT3 MICE OR INHIBITOR S3I-201 INTO RATS SUPPRESSED THE CXCL12 UPSURGE BY DECREASING THE ACETYLATION OF HISTONE H4. FINALLY, BLOCKADE OF CXCR4 BUT NOT CXCR7 AMELIORATED THE PACLITAXEL- OR VINCRISTINE-INDUCED MECHANICAL ALLODYNIA. TOGETHER, THESE RESULTS SUGGESTED THAT ENHANCED INTERACTION BETWEEN STAT3 AND P300 MEDIATED THE EPIGENETIC UPREGULATION OF CXCL12 IN DORSAL HORN NEURONS, WHICH CONTRIBUTED TO THE ANTITUBULIN CHEMOTHERAPEUTICS-INDUCED PERSISTENT PAIN. 2017 20 742 41 CANNABINOID CB2 RECEPTORS ARE UPREGULATED VIA BIVALENT HISTONE MODIFICATIONS AND CONTROL PRIMARY AFFERENT INPUT TO THE SPINAL CORD IN NEUROPATHIC PAIN. TYPE-2 CANNABINOID RECEPTORS (CB2, ENCODED BY THE CNR2 GENE) ARE MAINLY EXPRESSED IN IMMUNE CELLS, AND CB2 AGONISTS NORMALLY HAVE NO ANALGESIC EFFECT. HOWEVER, NERVE INJURY UPREGULATES CB2 IN THE DORSAL ROOT GANGLION (DRG), FOLLOWING WHICH CB2 STIMULATION REDUCES NEUROPATHIC PAIN. IT IS UNCLEAR HOW NERVE INJURY INCREASES CB2 EXPRESSION OR HOW CB2 ACTIVITY IS TRANSFORMED IN NEUROPATHIC PAIN. IN THIS STUDY, IMMUNOBLOTTING SHOWED THAT SPINAL NERVE LIGATION (SNL) INDUCED A DELAYED AND SUSTAINED INCREASE IN CB2 EXPRESSION IN THE DRG AND DORSAL SPINAL CORD SYNAPTOSOMES. RNASCOPE IN SITU HYBRIDIZATION ALSO SHOWED THAT SNL SUBSTANTIALLY INCREASED CB2 MRNA LEVELS, MOSTLY IN MEDIUM AND LARGE DRG NEURONS. FURTHERMORE, WE FOUND THAT THE SPECIFIC CB2 AGONIST JWH-133 SIGNIFICANTLY INHIBITS THE AMPLITUDE OF DORSAL ROOT-EVOKED GLUTAMATERGIC EXCITATORY POSTSYNAPTIC CURRENTS IN SPINAL DORSAL HORN NEURONS IN SNL RATS, BUT NOT IN SHAM CONTROL RATS; INTRATHECAL INJECTION OF JWH-133 REVERSED PAIN HYPERSENSITIVITY IN SNL RATS, BUT HAD NO EFFECT IN SHAM CONTROL RATS. IN ADDITION, CHROMATIN IMMUNOPRECIPITATION-QPCR ANALYSIS SHOWED THAT SNL INCREASED ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME3 AND H3K9AC) AND DIMINISHED OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AT THE CNR2 PROMOTER IN THE DRG. IN CONTRAST, SNL HAD NO EFFECT ON DNA METHYLATION LEVELS AROUND THE CNR2 PROMOTER. OUR FINDINGS SUGGEST THAT PERIPHERAL NERVE INJURY PROMOTES CB2 EXPRESSION IN PRIMARY SENSORY NEURONS VIA EPIGENETIC BIVALENT HISTONE MODIFICATIONS AND THAT CB2 ACTIVATION REDUCES NEUROPATHIC PAIN BY ATTENUATING NOCICEPTIVE TRANSMISSION FROM PRIMARY AFFERENT NERVES TO THE SPINAL CORD. 2022